Simon Willison Releases ttok 0.4 and Quickly Upgrades It to 1.0
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On October 9, 2026, Simon Willison released ttok 0.4, a token-counting CLI tool based on OpenAI's open-source tiktoken library. This version fixed a Click warning, updated the CI configuration, and added a --list-models command to list available models. ttok can be run via uvx, for example using cat file.txt | uvx ttok to count the tokens in any file. One hour later the same day (08:34), Willison released ttok 1.0, switching the default tokenizer from GPT-4 to GPT-5/GPT-6, using this change as the occasion for the 1.0 release. This is the entirety of the coverage on this event so far; no further developments.
AI overview of reporting · Updated 9 days ago
Developments
2 developments
- 10/9 08:34 · 1 reportsSimon Willison Releases ttok 1.0 with Updated Default TokenizerSimon Willison：ttok 1.0
- 10/9 07:34 · 1 reportsSimon Willison Releases ttok 0.4Simon Willison：ttok 0.4
Reporting timeline
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- Simon Willisonttok 1.0
Simon Willison switched ttok's default tokenizer from GPT-4 to GPT-5/GPT-6, and used the occasion to release version 1.0.
- Simon Willisonttok 0.4
Simon Willison released ttok 0.4, a CLI tool for counting tokens built on OpenAI's open-source tiktoken library. The update fixes Click warnings, updates CI, and adds a --list-models command to list available models. The tool can run via uvx, for example cat file.txt | uvx ttok to count tokens in any file.